Formation principle of cycloid of hypoid gear

The tooth milling of cycloid hypoid gear is designed according to the principle of “imaginary plane gear” (crown wheel, also known as plane generating wheel). In order to form the required long external cycloid (referred to as cycloid) in the gear hobbing process, assuming that Z0 groups of cutter teeth are installed on the end milling cutter head, each group of cutter teeth has at least two cutter teeth, outer cutter a and inner cutter I, which are used to process the concave and convex surfaces of the teeth respectively. The relative movement between the cutter head and the crown wheel can be regarded as a pure rolling of a drum on the cutter head around the base circle on the crown wheel. The inner and outer blades on the cutter head form a long epicycloid tooth line on the indexing plane of the crown wheel. When the cutter head turns a group of cutter teeth, the wheel blank and the production wheel turn a tooth to process the concave convex sides of the tooth groove.

(1) through the research on the split cutter head, forming principle and parameters of face rolling cutting method, the mathematical model of cycloid tooth hypoid large and small wheel is accurately established.

(2) the tooth surface contact analysis of cycloid Hypoid Gear Considering installation error is proposed. The concave longitudinal curvature is changed by adjusting the outer cutter radius, so as to obtain the ideal contact ellipse.

(3) cycloid hypoid gear has low sensitivity to installation error. By controlling the installation error, the meshing track position and transmission quality can be effectively improved.

As shown in the figure, when the cycloid tooth hypoid gear is hobbed, the rotary motion of the cutter head and the rotary motion of the workpiece are matched with a certain transmission ratio. The cutter head blade forms a long epicycloid tooth shape on the wheel blank, and enables the wheel blank to obtain continuous graduation between a certain number of teeth. This method is called continuous graduation double-sided method, also known as end face hobbing method.